For the therapy of respiratory tract diseases such as allergic or anallengic asthma or chronic or acute bronchitis, a xanthine derivative, a .beta.sympathetic nerve acceptor stimulating preparation and an anticholine preparation are used as a bronchial tube dilating preparation. These preparations ape used in various forms such as a tablet, a powder, granules, a suppository, syrup, an intravenous solution, a hypodermic solution, an intramuscular preparation and an inhalant. The preparation form is selected from these depending upon the disease graveness and age of a patient.
Further, for the therapy of the above diseases at an intermediate or higher graveness level in particular, a steroidal drug having anti-inflammatory activity is used. This drug is known to have not only anti-inflammatory activity but also a therapeutical effect on the incompetent state of a .beta.acceptor. This drug is mainly intravenously administered at present, while it is recently being emphasized that this drug has efficacy when administered by inhalation.
An anti-allergic drug is used as a drug for preventing respiratory tract diseases such as allergic asthma or chronic or acute bronchitis. This drug exhibits its effect by inhibiting the antagonistic activity to mediators such as histamine and leucotriene and the release of the mediators from mast cells.
Preparations according to Chinese medicine such as Ephedrea herba, Bupleuri radix and a fluid therapy agent are recently used alone or in combination for the therapy of the above diseases. Further, there are used specific therapies using allergenic extracts and a nonspecific alterative treatment agent using a gold preparation, bacterial vaccine and histamine-added .gamma.-globulin although the mechanism of the latter for producing an effect has not yet been made clear.
Respiratory tract diseases caused by a respiratory system disease are therapeutically treated depending upon the diseases. For example, in infectious diseases, an antibiotic is administered in addition to the above drugs.
In respiratory tract diseases (injury) caused by the inhalation of an acid or an organic solvent or by the inhalation of hot air, not only autotherapy is expected but also an anti-inflammatory preparation such as a steroidal drug or an antibiotic against a possible infectious disease is used.
A basic fibroblast proliferation factor (also called a basic fibroblast growth factor, to be referred to as "bFGF" hereinafter) is a peptidyl cell growth factor which has been recognized to be present in the pituitary, brain, retina, corpus luteum, adrenal, kidney, placenta, prostate, thymus, chondrosarcoma and macrophage of a human being and other specific mammals (Cell Growth Factor, Part II, compiled by Japanese Tissue Culture Society, Asakura Publishing Co.). In the beginning, it has been found that bFGF exhibits high proliferation activity in a fibroblast such as BALB/c3T3 (D. Gospondarowicz: Nature 249: 123, 1974), and it was named such due to this activity. Then, it has been also found that it promotes the proliferation of almost all cells from amesoderm, particularly an endothelial cell (D. Gospondarowicz: National Cancer Institute Monograph 48: 109, 1978) and also promotes the proliferation of satellite cells of skeletal muscle (R. E. Allen: Exp. Cell Res. 152: 154, 1984).
Further, the clinical application of bFGF to various diseases is being studied recently. For example, bFGF is clinically applied to the therapy of wound, and bFGF is also clinically applied to the restoration of a blood vessel using its vascularization activity.
Moreover, a fibroblast-derived epithelial growth factor has been recently found, and it may be therefore inferred that the production of the fibroblast-derived epithelial growth factor is increased since bFGF activates the fibroblast.
On the other hand, in the field of the therapy of respiratory tract diseases, studies of asthma and chronic or acute bronchitis are vigorously under way. In the studies, an inflammation reaction of a respiratory tract caused by inflammatory cells induced or allowed to infiltrate by various stimulants is studied in close-up, and impairments of a respiratory tract and bronchial epithelial cells and peeling of epithelial cells caused by the impairments attract attention as symptoms. It is therefore a drug having the promotion activity for restoring an impaired epithelial portion that is being desired as a therapeutical drug.
The present invention has been made in view of the above therapies and therapeutical studies of respiratory tract diseases. It is an object of the present invention to provide a novel preparation for the therapy of respiratory tract diseases, which can alleviate respiratory tract hypersensitivity and prevent respiratory tract diseases From becoming intractable or permit the therapy of intractable respiratory tract diseases by restoring that portion of a respiratory tract or bronchial tube where the epithelial cells are impaired or peeled, observed in respiratory tract diseases.